Presentation on theme: "PM S2 K5 Identify that cellulose contains the basic carbon structures needed to build petrochemicals and discuss its potential as a raw material."— Presentation transcript:
PM S2 K5 Identify that cellulose contains the basic carbon structures needed to build petrochemicals and discuss its potential as a raw material.
List two uses of raw cellulose (cellulose straight from the plant)
Option 1 – use cellulose as it is
Option 2 – modify the structure of cellulose -> modified properties
Option 3 Disassemble the cellulose and rebuild it. This is very simple!
Let’s do some equations to represent this.
Option 4 Use cellulose directly as an energy source. Humans have done this for a long time..how?
So cellulose does contain the basic carbon structures needed to build petrochemicals. As demonstrated by your equations.
The carbon-chain sections in cellulose could be changed to chemicals that, at present, are mostly made from petroleum eg. Propene, butene. If a chemical process can be developed or a micro-organism found that can break the glucose into these smaller carbon-chains this would be very useful.
Where does it come from?
Switchgrass – native to N. America. It is grown to produce cellulose ethanol.
Sugar cane- sugar can be fermented ethanol ethylene (this is another topic)… Waste products made of cellulose and can be turned into glucose ethanol ethylene …
Switchgrass has long roots…
Why is cellulose not used more widely?
Biomass is a huge resource. Two main obstacles are: 1- Cost- it takes a lot of energy to grow, harvest and then process the crops. We do not have economic technologies to process cellulose… yet..? 2- Land – Most fertile land is already being used to grow crops. Is it ethical to use land to grow crops entirely for their cellulose when people in Some parts of the world do not have enough to eat? Solutions?
Solutions 1- Research into making the conversion of cellulose into useful chemicals more economical. 2- Use waste products of crops that would normally be discarded.